1. Field of the Invention
The present invention relates to a signal processing device to which signals having a variety of transmission rates and frame formats are inputted, and to a signal processing method.
2. Description of the Related Art
At the present, there is diversification of fast digital communication technologies such as SONET/SDH (Synchronous Optical NETwork/Synchronous Digital Hierarchy), GbE (Gigabit Ethernet (registered trademark)), FC (Fiber Channel), FICON (FIber CONnection), SCON (System CONnection), etc. These communication technologies are utilized corresponding to communication services etc to be provided.
An OTN (Optical Transport Network) exists as a technology of transferring these diversified client signals across an optical core network. The OTN is defined as a next generation optical transmission network of which standardization is underway in the ITU-T (International Telecommunication Union Telecommunication Standardization Sector). The OTN has characteristics such as enabling a dynamic change of an optical path of a WDM transmission system, transmission of the variety of client signals as described above and high-reliability transmission by adopting a forward error correction (which will hereinafter be abbreviated to FEC) code and over head (which will hereinafter be abbreviated to OH).
A relay device in the WDM transmission system utilizing this type of OTN needs to monitor and set a type, a transmission rate, etc of a signal to be relayed. It is because the various types of client signals can not be flowed across (the relay device), unless thus done. In the conventional relay device, frequency information, a type of a frame format, etc of the processing target client signal have hitherto been set in a frequency detecting unit and a frame detecting unit within the relay device from a monitoring device etc connected to the relay device.
It is to be noted that an optical regeneration repeater of a bit rate automatic selection type is disclosed by way of a document of the prior art related to the invention of the present application in the following document. The conventional art document is “Japanese Patent Application Laid-Open Publication No. 10-313277.”
In the conventional relay device, however, a system administrator must manually set the frequency information and the type of the frame format while monitoring an alarm signal etc sent to a monitoring device etc. Hence, initial setting from the monitoring device etc is required each time the transmission rate and the frame format change due to switchover of a line etc, and a tremendous labor and much time are needed for flowing the signals through in such a case. Still more, at the present time when the signals increase in their types due to the diversification of the communication technologies, the initial setting involves expending greater amounts of labor and time.
As the types of the client signals, there are bit rates such as STS-3/12/48/192/768(SONET), STM-1/4/16/64/256(SDH), OPU1/2(OTN), 1GbE/10GLAN/10GWAN(GbE) and 1G/2G/4G(FC) for respective frame formats based on SONET/SDH, GbE, OPU (Optical Channel Payload Unit), 10GbE, FC, FICON and SCON according to the communication standards. Further, at the present, the long-distance WDM transmission and the metropolitan WDM transmission employ the following types of signals. These signals are exemplified such as OC192 signal+G.7090TU2 (10.7 Gbps), OC192 signal+U-FECOTU2 (10.7 Gbps), OC48×4/ODU1×4/ODU2+G.7090TU2 (10.7 Gbps), OC48×4/ODU1×4/ODU2+U-FEC OTU2 (10.7 Gbps), 10GLAN signal+G.7090TU2 (11.9 Gbps), 10GLAN signal+U-FEC OTU2 (11.9 Gbps), 10GWAN signal+G.7090TU2 (10.7 Gbps) and 10GWAN signal+U-FEC OTU2 (10.7 Gbps).
Moreover, in the optical regeneration repeater disclosed in the Patent document 1, a clock frequency is detected from an inputted data signal, and hence, in a case where the high-speed data signal is inputted, a device operating with a faster clock than the clock frequency is required. Further, if data with an unknown frame format is inputted, it is impossible to set the data signal in a status of flowing through the optical regeneration repeater.